Luckily I only had to pass through there, never staying more than a few days, but Al Udeid in Qatar is about the hottest I've personally enjoyed, and I've spent a good chunk of my life in Middle East, North Africa, and lived in Las Vegas for a spell. The poor troops stationed there would take 4-5 tshirts to work with them and just periodically change, since there was nothing you could do for the heat and sweat and humidity of that place. You get downrange to Iraq the low triple digits seems down right autumnal in comparison.